Topic: Anyone tried 3 spoke DYMAG wheels??

[754]

 Just picked up a Magnesium 3 spoke today  ..

 4.5 x 18 with a 6 inch slick and 46T sprocket and cush drive.. weighs 24lbs for all that.. 

 f you have run these what do you think of them...?

[simon#42]

have used them for years on my race bikes an have one in the back of my f2 , great wheels , have never seen one fail , i know people who have use them at the TT for 30 years !     make sure you make a proper cush drive if your using it on the road or the chain wont last long

[lordmoonpie]

+1 to what Simon said - they are fantastic wheels. Ran them for ten years on my Moriwaki VTR superbikes and never ever a concern with them. Also had them on my Ikuzawa signle that came 5th in the TT on them (not me on it sadly :-)) but they really are good wheels.

[BLUE71TURBO]

 They are total trash !!  You better send it to me so i can use i mean trash it for you !!     

[754]

 I took the wheel partly apart, needs a cush drive.. and dowel pins are loose. Plenty of meat there, I can get it back to new specs, with either a new or made by me billet cush housing.

 I am glad I got to see it internally, as it is a different approach than I have used on billet hubs to shave off weight. This is a first generation H beam mag 3 spoke. I visted a site called HPS in GB today, they have quite a few versions of Dymags, pretty cool, and very lightweight stuff.. I am VERY impressed.

 Looks like I can save about 20 lbs (or more) over the rear wheel assemblies I have run before.. that may help..

[Bill/BentON Racing]

They are FINE wheels,had one 18 inch on the back of the NS400. The day after I got it from PO my bud in MBSC mentioned how he wished he could find one for his Norton Commando project.....yes I gave it to him,old RR bud and former tech for me.Dave Buck you still owe me....lunch? ,Bill

[kayaker43]

The classic Dymags are my favorite wheels. I have several sets waiting to go on project bikes. Corrosion is their only enemy. Take refinishing very seriously if you need to do it. After stripping ALWAYS have them crack checked! You can actually buy a kit to do dye penetrant testing at any welding supply store and do it yourself. Many of these wheels use aluminum center hub parts that are epoxied into the magnesium casting. Some are one piece with bolt on adapters and cush drives. Take this into consideration if planning to powder coat them. The epoxied versions won't fare too well if baked at too high a temperature. Make sure your powdercoater uses no more heat than neccessary to bake and you should inquire about low temperature powders. If you don't express some concern, they may try to burn off the old coating in the oven to save time sandblasting.

Magnesium should always be chromated after blasting and before refinishing. Otherwise corrosion will happen under the coating eventually. Fortunately there are newer chemicals that you can apply yourself http://www.aircraftspruce.com/catalog/cspages/preKote.php  

[kayaker43]

If you can't fit a tire that wide I have some 4 inch Dymag wheels I might trade?

My 120+ HP TZ750 has Dymags with no cush drive and a narrow chain! It had a long hard racing life and the gearbox looks like new. The stock TZ wheels have no cush drive either. I ran Dymags without cush drive on my CB550 racer for 5 seasons. Many of the old 1025 superbikes I've seen didn't run cush drive.

Even though common sense says otherwise, I've never seen any evidence of more wear or damage to chains or gearboxes even on high HP bikes with no cush drive?? Drag racing may be the only place I would consider using one??

To be honest, I never noticed any more harshness without cush drive and I do like the "direct" feel with less backlash. I'm curious what other people think who have used direct drive?

[754]

Thanks for the info.
 I had a nice wheelset before, I sold with a Harley project. It had an aluminum 12 spoke front, and a magnesium American Racing 12 spoke on back. I had real doubts about wether to powdercoat or not.. mainly due to the 400 dgree curing.. Sold the bike guy offers the wheels back years later, but had powdercoated..  I did not really want it coated, plus he wanted 800 for both.
 
 Fast forward to now, I doubt I would powder a real mag, just dont trust the heat of curing.
 The 18 x 4.5 was dragraced and is from an 85 GSXR. Cushdrive  holder is dowelled into main wheel hub, and is worn.. the gluing makes sense as there is a sort of knurl there.. disc side is tight.

 The dowels are a bit loose, I can oversize the holes and make a stepped dowel or drill a fresh pattern.. I am very impressed by the design and the fact that I can still redrill for a new pattern to bring it back to specs. It had a 7 inch wrinklewall tire on it (6.75 wide), I imagine it took quite a pounding.. The cush drive carrier is there but has cracks by the dowels, and the doughnuts part has a chunk missing on the side of 1. Will make a new one from 6061, it appears carrier may be aluminum, not magnesium?

 I am not dead set on cush drive, Morris does not use them.. but will use it here as all the parts/pattern,  are there. Also I dont dump the clutch on the line, I slip it first 50 feet.

 Width wont be a problem , will build a swingarm, have 2 pces of 1.75 x 1.0  steel tubing, already milled for axle slots..
 You have a TZ that is pretty cool, loved thge trtacker TZ that the guy from Powroll built.. Trackmaster frame.. we saw it in 09 at the Bonneville GP..

[scottly]

 I am not dead set on cush drive, Morris does not use them.. but will use it here as all the parts/pattern,  are there. Also I dont dump the clutch on the line, I slip it first 50 feet.

My Morris has a cush drive, of sorts. I should have taken pics before I put it back together last week. It appears to be urethane biscuits, with steel centers, about 3/8" thick. The biscuit's steel centers are pinched between 4" OD steel "washers" on either side of the sprocket, and the sprocket floats on the OD of the biscuits, captured between the "washers".

[754]

 I have one of them Morris cush drives, but no Morris rear wheel.at least not a wide enough one..
 Scottly a set of real mags would get you under 390 lbs.. check your PM..

[scottly]

Hey Frank, thanks, but I will have to do the best I can with the parts I have. I shaved 80 grams off the front wheel assembly in the last couple of days substituting aluminum for steel bearing spacers, more to come when I figure out how to drill the Yamaha slotted discs. Also, I have learned (hope it's true) that since my Morris wheels are marked "TL", I can run them with tubeless tires. That should be worth 8 pounds alone!!    

[City Boy]

Hi gang.I have a Morris alum. rear on my Cobra that originally had his cush drive.All the sprocket bolts sheared one day on the street.I removed the cush drive and increased the bolt size from the stock 5/16 to 3/8 and had no further issues.I also like the feel of no cush.   Rock On